gracet,
I don't recommend playing with the registry unless you've created a backup to restore if required. I'm also not an IT expert - but this is what I did:
Firstly - set your QAT and custom tools as you want them in Nitro then:
1. access the registry editor
2. go to HKEY_CURRENT_USER > SOFTWARE > Nitro > Pro
3. select the folder for the version you're running (i.e. 11.0)
4. go to SETTINGS
5. right-click on QAT folder and select EXPORT.
6. give the file a meaningful name (e.g. QAT Key) and save it to a convenient location (i.e. Desktop).
7. repeat steps 5 and 6 for the TOOLS folder.
Like I said - it's a only a workaround, but it's much faster than manually resetting every single customisation each day!